Proteus syndrome with progressive paralysis of the unilateral lower limb: A rare case report and literature review.

Objective: Proteus syndrome, a rare disorder with an incidence of one in a million, is characterized by connective tissue nevi, asymmetric limb overgrowth, and abnormal subcutaneous adipose tissue distribution. Limited awareness of this condition often hinders accurate clinical diagnosis. We report a case of Proteus syndrome with concurrent progressive paralysis in the unilateral lower limb, aiming to enhance understanding of the disease and its associated complications. Methods: The patient, an 11-year-old male, has been conclusively diagnosed with Proteus Syndrome. This diagnosis was established by analyzing clinical manifestations, imaging studies, and laboratory tests. In addition, a literature review was conducted to systematically elucidate the etiology, diagnosis, treatment, and prognosis of this condition. Results: According to the clinical manifestations, we confirmed a case of Proteus syndrome. This example exhibits the general characteristics of patients with severe hemihypertrophy of the bilateral lower limbs, anomalies in hypodermic and adipose distribution, and unilateral lower limb progressive paralysis. Pathological biopsy confirmed the right chest wall mass as a lipoma. Notably, the patient experiences lower limb movement disorders caused by intraspinal disease. At the same time, the gene sequencing results of this Proteus syndrome patient showed mutations in the IDUS gene and SPECC1L gene, which have not been reported before. Conclusion: We diagnosed Proteus Syndrome with lower limb sensorimotor abnormalities, which may be caused by mutations in the IDUS gene or SPECC1L gene. This is the first report of these kinds of gene mutations in association with Proteus Syndrome.